Natural carotenoids such as β-carotene, lycopene, lutein and fucoxanthin were extensively studied because of their anti-tumor characteristics as well as prominent free radical elimination functions. Recent studies found that some carotenoids had more specific and unique pharmacological functions. For instance, some reports alleged that fucoxanthin had a weight reducing function. Fucoxanthin, also called pheophytin, is the pigment contained in brown diatoms, chrysophrys and yellow-green algae. It takes part in the photosynthesis as parts of the photochemical system II. Separated from the algae, it is red-brown crystal. Being a kind of xanthophylls, it renders brown color to the brown algae and thus is the characteristic pigment in brown algae. It is also sporadically contained in the diatoms and other algae. Sometimes it is confounded with phycophaein, however the latter is considered to be the characteristic water-soluble pigment in the brown algae, it seems to be a imaginary material, and is an yellow-brown oxidation product of a phenolic compound contained in the brown algae after death of these plants. Therefore fucoxanthin and phycophaein are essentially different substances. The results of studies showed that fucoxanthin regulates high expression of the uncoupling protein (UCP1) gene in the animal white adipose tissue (WAT), causing the decrease of fat contents in the entrails. Experiments verified that fucoxanthin reduced the amount of WAT in rats and fat KK-Ay mouse. Mediated by fucoxanthin, the expression of UCP1 in the WAT expedites the oxidation of fatty acids. (Maeda H, Hosokawa M, Biochem. Biophys. Res. Commun., 2005, 332(2):392-397; Maeda H, Hosokawa M, Int. J. Mol. Med., 2006, 18(1):147-152; Miyashita K, J. marine Bioscience and Biotechnology, 2006, 1(1):48-58). In spite of all the recognition to the weight reducing function of fucoxanthin, however, it should be recognized that weight-reducing is a compositive process with many physiologic biochemical reactions involved in vivo and the application of a single component cannot result in an ideal effect. Therefore, a fucoxanthin composition with distinctively synergic function is needed in this field to exert a weight reducing function.
Tocotrienols are a kind of functional components contained in palm oil and rice bran oil, their chemical structure is similar to tocopherol. Recent studies showed that they are superior in physiologic functions to tocopherol. Vitamin E is very important in every growth phases of various animals, and is absolutely necessary for the exertion of optimal function of the procreation, muscle, nervous and immune systems. Among vitamins, α-tocopherol, usually called Vitamin E, has the highest activity and widest distribution and is the most representative, hence it has been the focal research subject. However, recent studies found that tocotrienols showed more prominent characteristics than α-tocopherol in some cases, such as anti-oxidation, anti-tumor and cholesterol-lowering activities. These special functions of tocotrienols are related to its structure. As tocotrienols have an unsaturated side chain, they are able to more effectively penetrate into the organs containing saturated fatty acid layers, such as the brain and liver, and it is easier for them to distribute into the lipid layers of the cell membranes, thereby performing a better functions of anti-oxidation as well as cleaning up free radicals. To date tocotrienols are studied in depth abroad, whereas they are studied relatively less in China, especially on their efficacy in the applications in weight reduction.
The seas are vast in our Earth and the sources of alga plants in the sea are abundant, fucoidans are gradually becoming one of the main sources of biological polysaccharides. Owing to the special living environment of the sea algae, fucoidans have some unique biological activities, for example, laminarin is capable of decreasing the superoxide content in the spleen and increasing the activities of superoxide dismutase (SOD) as well as catalase (CAT), thereby achieving antitumor purpose; porphyra polysaccharide and propylene glycol mannate sulfate (PGMS) have the functions of anti-thrombus and improving microcirculation; laminarin and porphyra polysaccharide etc. may have the function of protecting the cells of organisms. More and more researches have shown that fucoidans have enormous prospect of being exploited and applied. Brown algae polysaccharides, included brown algae carbohydrate gum, brown algae gum and brown algae starch, are the important components of fucoidans.
In recent 10 years, Japanese scientists studied brown algae extensively and thoroughly with thousands of paper published. These papers involve the analysis of chemical constituents of brown algae, the researches on their pharmacological effects and their potential medicinal applications as well as new applications in health protection, etc. Researchers found that brown algae polysaccharides have many physiological activities including effects of antitumor/increase of human immunity, anti-allergy, liver-protection, anti-coagulation, cleaning-up of the physiological environment of intestinal tracts, decreasing the blood fat content, anti-ulcer, decreasing blood sugar, skin wetness reservation, etc. Therefore, it was proposed that fucoidan and the like have the potential to be the materials of many new medicines.
Among various brown algae polysaccharide materials separated to date, the fucoidans are the most concerned by the scientific researchers owing to its pharmaceutical activities. Because not only the fucoidan contents in many algae are relatively high, but they have many pharmacological functions. It is most probably that they are exploited as the materials of new medicines. More delightfully, fucoidans have a number of interesting advantages. Firstly, they are water-soluble (as they belong to compounds of sulfate kind); secondly, fucoidans are easily absorbed by human body and they show no significant poisonous effect on human bodies. Presently Japanese researchers have separated 3 fucoidans with different molecular structures, i.e., G-, F-, and U-fucoidan. Results of animal experiments using the 3 fucoidans showed that they all have strong effects of facilitating the apoptosis of tumor cells (the effect of inhibiting the growth of tumors), equilibrating the immunity and promoting the regenesis of organism cells in the body, etc. It is hopeful that these 3 types of fucoidans can be exploited to be new clinic anti-tumor medicines.
Currently the studies on the weight reducing effects of fucoxanthin extract have got on primary advancement. However, the weight reducing effect is not yet ideal when it is used as the sole components and few studies has been carried out on the compositions of fucoxanthin extract.